Flight control systems for devices, such as missiles, include control surfaces, such as fins, that are movable and controllable during flight. When the devices are carried on an exterior of an aircraft, for example under a wing, the devices are subjected to high aerodynamic loading. This loading causes the control surfaces to move in the direction of the load. When the control system is turned on, the system usually is unable to recognize that the control surface has been moved, and therefore a flight path of the device will not be accurately controlled. The loading also puts loads on a control mechanism for the control surface that may cause failure or fatigue that would further prevent the device from being accurately controlled.
To avoid high aerodynamic loading, a locking device may be provided to lock the control surface in a selected position. The control surface may be locked in a null position from which it is released only on command from the control system. The locking device may be resettable, for example, to permit the control mechanism to undergo preflight testing.